One-way valve for delivering a free-flowing material

ABSTRACT

A one-way valve for the recontamination-protected repeated discharge of a flowable material from a container of a preferably reducible volume contains a valve seat which consists of a rigid plastic material and which is arranged in the container neck and comprises a base body which rests on the inner wall of the container neck and contains at least one through hole, and a projection which extends in axial direction of the container neck towards the exit opening. The valve seat has arranged thereabove an elastic seal which comprises an annular section covering the at least one through hole, and a sleeve-like section which surrounds the projection at a radial distance with the exception of its end section which in the closed state of the one-way valve rests in the exit opening on the end section of the projection. A sterilization element of silver or of another metal having an oligodynamic action may be arranged in the intermediate space between the projection of the valve seat and the elastic seal. The application of pressure to the contents of the container has the effect that the annular section of the seal releases the at least one through hole of the valve seat, the end section of the sleeve-like part of the seal exiting from the exit opening and releasing the same. The seal will then return into the initial state. The contents of the container is safely sealed against the ingress of contaminants.

The present invention relates to a one-way valve for discharging aflowable material from a container of a preferably reducible volume,comprising a cap which is seated on the container neck and has an exitopening for the material.

The container having a reducible volume may e.g. be a rigid outercontainer with an inner container or inner pouch consisting of a softmaterial, which after part of the flowable material has been dischargedcontracts each time accordingly, with pressure compensating openingsbeing provided in the outer container for pressure compensation betweenthe rigid outer container and the inner container. The container,however, may also be single-walled and e.g. have the shape of a tubewhich is gradually compressed for discharging the material. As furtherexamples of a container having a reducible volume, reference is herewithmade to, bellows-type containers which gradually collapse in proportionto the discharge of the flowable material, and to syringes whose volumecan be reduced by advancing a syringe plunger. It goes without sayingthat the above enumeration is only by way of example.

The container, however, need not be of a reducible volume. Compensationmay also be achieved through inflowing air flowing through a filter(sterile filter). The flowable material may be a liquid, or it may be acream, gel, ointment, or another substance, optionally of a highviscosity.

The one-way valve of the above-considered type is meant to discharge theflowable contents of the container in individual partial amounts ordoses and, depending on the application, the flowable contents may bedischarged in doses, distributed over a prolonged period of time.

When many types of flowable materials are discharged, it is importantthat the material remaining in the container should not be impaired bythe ingress of foreign matter, be it microorganisms or inorganic ororganic impurities. Above all in pharmaceutical, but also e.g. incosmetic flowable materials, this determines the quality, but is e.g.also applicable to substances to be counted among foodstuff. That is whythe material volume discharged from the container must not becompensated by air entering into the container if a situation is to beprevented where bacteria, dust, moisture, etc. get into contact with theremaining contents of the container. That is why, as has been mentionedabove, the volume must be reduced in the container in question inproportion to the amount of material discharged. It must above all beensured that no microorganisms penetrate through the container openingand contaminate the remaining contents of the container.

It is the object of the present invention to indicate a one-way valve ofthe type in question in which the sterility of the flowable materialremaining in the container is substantially guaranteed.

This object is achieved according to the invention by the features ofpatent claim 1.

Advantageous developments of the invention are characterized in thedependent claims.

The one-way valve according to the invention contains a valve seat whichconsists of a rigid plastic material such as PE/PP and is arranged inthe container neck.

When the container has, for instance, a continuous tubular shape, thevalve seat is inserted in the end section of the container.

The valve seat contains a basic body which rests on the inner wall ofthe container neck and comprises at least one through hole that whenreleased allows for the passage of the flowable material towards theexit opening of the container. Furthermore, the valve seat has aprojection which is connected to the basic body and which extends inaxial direction of the container neck towards the exit opening of thecontainer.

Furthermore, the one-way valve according to the invention comprises anelastic seal which comprises an annular. section which covers the atleast one through hole and has a sleeve-like section which is integrallyformed therewith and which surrounds the projection, which is preferablyarranged in the center in the container neck, at a radial distance withthe exception of the end section of the sleeve-like part which in theclosed state of the valve preferably rests inside the exit opening ofthe container on the end section of the projection. The annular sectionof the elastic seal is here pressed radially outside of the at least onethrough hole of the valve seat against the valve seat.

Moreover, the one-way valve preferably contains a sterilization meanswhich is arranged in the intermediate space between the projection ofthe valve seat and the sleeve-like section of the elastic seal, andexerts a bactericidal effect on bacteria that have possibly penetrated,etc.

The sterilization means may be a preferably spiral-like sterilizationelement which surrounds the projection, or it may be formed by coatingat least parts of the valve seat and/or the seal with theoligodynamically active material or the bactericidal substances.

In the one-way valve of the invention, the valve seat closes thecontainer neck, except for its at least one through hole, or if such aneck is not formed, the cross-section of the container positioned infront of the exit opening. In the closed state of the valve, the elasticseal firmly rests on the base body of the valve seat because it ispreferably held with its annular outer portion in contact with the valveseat, preferably pressed by an annular projection of the cap of thecontainer against the valve seat. The elastic seal which lies flat onthe base body of the valve seat thereby closes the at least one throughhole of the valve seat.

Furthermore, the elastic seal rests with the end section of itssleeve-like section tightly on the head end of the preferably pin-shapedprojection, namely inside the exit opening of the container in such away that said exit opening in the closed state of the valve is tightlyclosed. Due to the tight contact with the pin- or peg-shaped projectionof the valve seat it is also ensured that no impurities can penetratefrom the outside between the projection and the sleeve-like section ofthe seal.

When pressure is exerted on the contents of the container, preferably byapplying an external force to the container, the flowable material ispressed through the at least one through hole of the valve seat againstthe annular section of the elastic seal positioned thereabove, wherebysaid seal is lifted from the base body of the valve seat. This has theconsequence at the same time that the end section of the sleeve-likesection of the elastic seal is lifted from the end section of theprojection of the valve seat, i.e. it is moved in axial direction of thecontainer neck and preferably projects from the exit opening of thecontainer. The flow path through the exit opening of the container isthereby released for the flowable material which has passed through theat least one through hole of the valve seat.

When pressure is no longer exerted on the contents of the container, theseal will return due to its elasticity into its initial position inwhich the at least one through hole of the valve seat and the exitopening of the container are closed.

Even if microorganisms enter into the space between the elastic seal andthe valve seat through the opening area of the container, thesterilization element arranged there would efficiently prevent a harmfulpropagation of microorganisms, so that the sterility of the containercontents is ensured. This is true for both the flowable materialremaining between the seal and the valve seat, and the contents of thecontainer remaining below the one-way valve.

The flowable material can be discharged not only by exerting pressure onthe contents of the container, but also by exerting a negative pressurefrom the outside on the elastic seal and, after the same has beenopened, on the contents of the container.

It is suggested in further details that the base body of the valve seatshould be equipped, radially outside the projection, with a plurality ofthrough holes that should be evenly distributed over the circumference.To this end the through holes may have the shape of slots formed in themanner of a circular arc.

Preferably, it is intended that the base body of the valve seatcomprises a planar base plate through which the at least one throughhole extends, and a circumferential wall adjoining the inner wall of thecontainer neck, which rests with an outwardly surrounding annularshoulder on the edge of the container neck. Like the container neck, thecircumferential wall has in general a circular cylindrical shape. Thecap of the container rests on the upper edge of the circumferential wallof the valve seat, whereby the valve seat is fixed.

The cap may be a screw cap. However, the cap may e.g. also be snappedonto the container neck.

The projection which is preferably attached in the center on the planarbase plate of the valve seat has in general the form of a pin or peg andmay be designed such that it has the shape of a circular cylinder with apreferably conically tapering end section.

Alternatively, the projection may have an arcuate contour inlongitudinal section; other shapes are also possible as long as the endsection of the projection provides for an appropriate sealing surfacefor the sleeve-like section of the elastic seal.

Advantageously, the upper edge of the projection of the valve seat isarranged inside the container opening, the edge being in alignment withthe upper side of the cap. It goes without saying that the diameter ofthe end section of the projection is smaller than the diameter of thecontainer opening because the end section of the sleeve-like section ofthe elastic seal is arranged in the annular intermediate space.

The annular section of the elastic seal has preferably also a planarshape and is held in the area of its circumferential edge in contactwith the planar base plate of the valve seat. Preferably, the closingcap of the container has an annular projection which presses the elasticseal in the above-indicated area against the valve seat. The annularsection of the seal may also be held by other means on the valve seat,e.g. by gluing.

The sleeve-like section which adjoins the annular section of the sealand which is also formed in the center may first be configured to becircular and cylindrical in longitudinal section, starting from theannular section, and then to be conical. In an alternative form, thesleeve-like section has an arcuate contour in longitudinal section.

The end section of the sleeve-like part of the elastic seal has an innercontour corresponding to the circumferential surface of the head sectionof the projection and rests with the exterior surface on the wall of thecontainer opening, the wall cross-section of the end section of thesleeve-like part having substantially the form of a wedge. Said sectionwhich, when viewed in cross-section, expands substantially in the formof a wedge towards the end closes the annular gap between the headsection of the projection of the valve seat and the inner wall of thecontainer opening in the closed state of the valve, the cross-sectionalshape promoting the tight closure due to the restoring force of theelastic sealing material.

A tight closure may also be ensured in addition by manually pressingback the end section of the sleeve-like part of the seal if the sealdoes not return automatically into the entirely closed state, which maypossibly be the case with highly viscous materials.

The sterilization element which is arranged in the intermediate space(dead volume) between the seal and the valve seat surrounds theprojection of the valve seat preferably in a spiral form. The dimensionsare expediently chosen such that the sterilization element which mayhave the shape of a helical spring is, on the upper end portion of theprojection, in contact with both said end portion and the sleeve-likesection of the seal, so that microorganisms possibly entering into theexit opening of the container are bound to get into contact with thesterilization element if they migrate downwards. Microbial contaminationis safely prevented thereby.

The sterilization element consists of silver or contains a silvercoating which develops a sterilizing effect. Instead of silver, it isalso possible to use other metals having an oligodynamic action, orbactericidal substances.

Further details of the invention become apparent from the followingdescription of a preferred embodiment and from the drawing, in which:

FIG. 1 shows an exploded view of the components of an embodiment of theone-way valve of the invention with associated container neck andcontainer cap;

FIGS. 2A and 2B show a side view and a top view of the valve bodyaccording to FIG. 1;

FIGS. 3A and 3B show a side view and a top view of the valve seataccording to FIG. 1;

FIGS. 4A and 4B show a side view and a top view of the container capaccording to FIG. 1;

FIGS. 5A and 5B are longitudinal sections through the one-way valve ofFIG. 1 as mounted on the container neck, in the closed and in the openedstate.

The main components of the sterile valve according to the invention area valve seat 1, an elastic sealing body 2 and, preferably, asterilization element 3 which are arranged in the neck 4 of a container5 in a way described further below. Moreover, a container cap 6 which isconfigured in a special way cooperates with the components of thesterile valve.

The valve seat 1 consists of a planar base plate 7 with an adjoiningcylindrical circumferential wall 8 which tightly rests in the installedposition on the inner wall of the container neck 4 and ends in anoutwardly oriented annular collar 9 that rests on the upper edge of thecontainer neck 4.

The base plate 7 includes four through holes 10 that are shaped in theform of a circular arc and are evenly distributed in circumferentialdirection.

In the center of the circular base plate 7, a pin-like projection 11 isformed that projects from the base plate 7 at a right angle and has acircular cylindrical shape which passes into an end section 12 which isshaped in the form of a truncated cone and projects beyond the annularshoulder 9.

Like the valve seat 1, the sealing element 2, which consists of anelastic plastic material, is also produced in one piece and includes aplanar annular section 13 which on its radial inner circumferential edgepasses into a sleeve-like section 14 whose central longitudinal axisextends in a direction perpendicular to the plane of the annular section13. Starting from the annular section 13, the sleeve-like section 14consists of a first circular cylindrical section 15, an adjoiningcentral section 16 tapered conically upwards, and an end section 17which has again a circular cylindrical shape on its outer contour. Theend section 17 has a wall thickness continuously increasing towards itsfree end because its inner contour extends conically in alignment withthat of section 16. The upper edge of the sleeve-like section isdesignated by reference numeral 18 while the upper edge of theprojection 11 is provided with the reference numeral 19.

The closing cap 6 of the container 5 contains an upper end wall 20 and acircumferential wall 21 of a substantially circular cylindrical shape. Aflat indentation 22 is formed on the inside of the circumferential wall21 and ends on a radially inwardly oriented annular collar 23 whichforms the upper side of an obliquely inwardly oriented surrounding nose24. Said nose 24 grips below a surrounding outer projection 25 on theoutside of the container neck 4 when the cap 6 is snapped onto thecontainer neck 4.

Radially inside the circumferential wall 21, the bottom side of theupper end wall 20 of the cap 6 has formed thereon an annular projection25 which has such an extension that in the installed position of thesterile valve and the cap 6 it presses the annular section 13 of thesealing body 2 firmly against the base plate 7 of the valve seat 1.

In the middle of the upper end wall 20 of the cap 6, a circular roundexit opening 27 is provided for the flowable material received in thecontainer. Viewed in cross section, the exit opening 27 is firstslightly narrowed, starting from the upper side 28 of the cap 6, toincrease more and more in width again after a cross-sectional rounding29. Viewed from the upper side 28 of the cap 6, the edge contour of theexit opening 27 extends in longitudinal section first in arcuate fashioninwards and then outwards again, which is followed by a section which isoriented obliquely outwards. In the area of the smallest place, the exitopening 27 is smoothly rounded.

FIGS. 5A and 5B show that the sterilization element 3 which is providedwith a silver coating and has the shape of a spiral screw or spiralspring surrounds the projection 11 of the valve seat 1 at a smalldistance. The cavity 30 which is defined by the sleeve-like section 14of the sealing element 2 and the projection 11 and through which theflowable material flows while being discharged in doses is narrowed,viewed in cross section, in the manner of a wedge towards the upper endsuch that the sterilization element 3 touches the sealing element in theupper area. This is not the case in the lower area of the sealingelement where the intermediate space between the sealing element and theprojection has a considerable width.

In the installed position of the sterile valve, the upper side 19 of theprojection 11 extends flush with the upper side 28 of the cap 6. This isalso true for the upper side 18 of the sleeve-like section 14 when thesterile valve is closed, i.e. when the annular section 13 rests flat onthe base plate 7. In the closed state, the upper end section 17 of thesleeve-like section 14 of the sealing element 2 completely fills theannular gap between the head end 12 of the projection 11 and thecircumferential wall of the exit opening 27.

When pressurized flowable material is pressed through the through holes10 in the base plate 7 of the valve seat 1, the radially inner area ofthe annular section 13 of the sealing element 2 is lifted upwards, asshown in FIG. 5B, which has the effect that the whole sleeve-likesection 14 moves upwards and the end section 17 of the sealing elementwhich has so far provided for the sealing action exits upwards out ofthe exit opening 27. This movement is a smooth one due to the conicallytapered outside of the end section 12 of the projection 11 and therounded perforated wall.

When pressure is no longer exerted on the contents of the container, thesealing element 2 will automatically return into its initial positiondue to the elasticity of its material. The restoring force can here bedefined by selecting a suitable elastic material and suitable dimensionsespecially for the wall thickness of the annular section 13.

1. A one-way valve for discharging a flowable material from a containerof a reducible volume, comprising a cap which is seated on the containerneck and includes an exit opening for material, comprising a valve seatwhich is arranged in the container neck and comprises a base body whichrests on an inner wall of the container neck and contains at least onethrough hole, and a projection which extends in an axial direction ofthe container neck towards the exit opening, and an elastic seal whichcomprises an annular section which covers the at least one through hole,and a sleeve-like section which surrounds the projection at a radialdistance with the exception of its end section which in the closed stateof the one-way valve rests in the exit opening on the end section of theprojection.
 2. The one-way valve according to claim 1, wherein asterilization means is arranged in the flow path of the flowablematerial.
 3. The one-way valve according to claim 1, wherein the basebody contains a plurality of through holes radially outside of theprojections.
 4. The one-way valve according to claim 1, wherein the basebody comprises a planar base plate which contains the at least onethrough hole, and a circumferential wall which rests on the inner wallof the container neck and which with an externally surrounding shoulderrests on the edge of the container neck.
 5. The one-way valve accordingto claim 1, wherein the projection of the valve seat has a circularcylindrical shape with a tapering, preferably conically beveled, endsections.
 6. The one-way valve according to claim 1, wherein theprojection of the valve seat has an arcuate contour in longitudinalsection.
 7. The one-way valve according to claim 1, wherein an upperedge of the projection is arranged inside the container opening.
 8. Theone-way valve according to claim 1, wherein the annular section of theseal has a planar shape and is held by an annular projection of the capradially outside of the at least one through hole in contact with thebase plate of the valve seat.
 9. The one-way valve according to claim 1,wherein the sleeve-like section of the seal in longitudinal section,starting from the annular section, is configured to be firstcylindrical, then conical and then cylindrical again on its outside. 10.The one-way valve according to claim 1, wherein the sleeve-like sectionin longitudinal section has an arcuate contour.
 11. The one-way valveaccording to claim 1, wherein the end section of the sleeve-like sectionhas an inner contour corresponding to the circumferential surface of theend section of the projection and, moreover, rests with it outer wall onthe narrow, which is rounded in cross section, of the wall of thecontainer opening, so that the annular gap between the end section ofthe projection of the valve seat and the inner wall of the containeropening is tightly closed in the closed state of the one-way valve. 12.The one-way valve according to claim 1, wherein the upper edge of thesleeve-like section of the seal is in alignment with the upper side thecap in the closed state of the valve.
 13. The one-way valve according toclaim 1, wherein the sterilization means is a spiral-like sterilizationelement which surrounds the projection.
 14. The one-way valve accordingto claim 1, wherein the sterilization element in the closed state of thevalve is, on the upper end portion, in contact with both the projectionand the sleeve-like section of the seal.
 15. The one-way valve accordingto claim 1, wherein the sterilization element consists of silver or ofanother metal having an oligodynamic action, or of a substance having abactericidal action, or is coated therewith.
 16. The one-way valveaccording to claim 1, wherein the sterilization means is formed bycoating at least parts of the valve seat and/or the seal with metalshaving an oligodynamic action or with substances having a bactericidalaction.